Energy Intensity and Carbon Dioxide Emissions
Many people are concerned about climate change, as well as emissions of carbon dioxide, which are believed to drive climate change, and energy use, which is primary source of carbon dioxide emissions. So, how is the U.S. doing on controlling carbon dioxide emissions and energy use, and how well are we likely to do in the future?
The Energy Information Administration ("EIA") reports that the per capita use of energy "was fairly constant" form 1990 to 2007, but began to decrease after 2007. The EIA projects that the U.S. population will increase by 25 percent from 2010 to 2035, but that the nation's energy use will only increase by 10 percent over that period. That translates into an annual decrease in per capita energy use of 0.5 percent per year during the period 2010 through 2035.
The EIA projects that the per capita level of energy-related emissions of carbon dioxide will decrease at an average rate of 1 percent per year from 2005 to 3035. The EIA projects that the total energy-related emissions of carbon dioxide in the U.S. will increase by 3 percent over that period.
Per dollar of gross domestic product, energy use decreased at an average rate of 1.7 percent per year from 1990 to 2010, and the EIA projects that the decrease will continue in the future.
The per capita decreases in energy use and carbon dioxide emissions, as well as the decrease in energy use per dollar of GDP, are illustrated in the first graph below.
The decreases are driven by several factors, including increased energy efficiency and increased use of energy sources other than fossil fuels. Another factor has been the relative shift in the U.S. economy toward service industries and away from manufacturing. This shift is illustrated in the second graph below, which shows a very small increase in GDP from industrial sectors of the economy and a substantial increase in GDP from service sectors.